It is now thought that the surgical removal of eyes containing choroidal malignant melanoma has helped the spread of tumor cells to other parts of the patient rather than the intended purpose of removing all the tumor cells to avoid such dissemination. It has been found that pressures within the eye rise dramatically during an enucleation or eye removal. It is believed that such pressures may cause showers of tumor cells into the blood stream of the patient.
In a previous attempt to prevent the possibility of such a release of tumor cells, a device for freezing a tumor in an eye has been developed. This device comprises a loop or tube through which liquid nitrogen is flowed to freeze the tumor and the area surrounding it. The loop may be adjusted to the size of the tumor. When this device is used the first stage of the operation is to surgically enter the eye cavity and separate the eye from connecting tissue until the area of the tumor is reachable. The device is then placed with the loop encircling the tumor and liquid nitrogen is intermittently passed through the loop to maintain a continuous freeze around the tumor. When the tumor is solidly frozen the remaining connective tissue may be separated from the eye and the eye may be lifted from the socket fixed to the loop through which liquid nitrogen flows.
This device causes some difficulty in that there is a tendency for adjacent tissue to freeze causing sticking of the eye to the adjacent orbital contents. It is necessary to protect adjacent structures from freezing with thin, sterilized sheets of styrofoam. Moreover, many tumors of the type which necessitates removal of the eye are located at the back of the eye. If this previously designed device is to be used considerable surgery must be carried out in order to place the freezer loop in a suitable position. The positioning of the loop is sometimes difficult and may, in some cases, be impossible.